Figure 2.

PROP Study Protocol Time Line spans from birth to one year of corrected age collecting health data and biospecimens. *Tracheal aspirate samples were collected if the infant was intubated and clinically required suctioning. ^#Physiologic challenge testing was either from oxygen to room air (21% oxygen, the “Room Air Challenge”) or from room air to 15% oxygen (“hypoxia challenge”) depending on status. NIRA: Non-invasive respiratory assessment; GERD: gastroesophageal reflux disease; iPFT: infant pulmonary function testing.